16
Stage 4
Topcoating and Finishing
Topcoating the roof
The Topcoat is a resin and should be treated in the same way as the base resin. It requires the addition of hardener for it to cure.
Always try to apply the topcoat immediately after the laminate is semi-cured (can be walked on, no stickiness) If this is not possible then
ensure topcoating is carried out within 24 hours to gain good bonding with the laminate. If the topcoating is left longer than 24 hours then
wipe down the laminate with acetone to gain a good bond of the topcoat to the laminate.
Remove the lid and stir the topcoat well before use. Ensure the styrene and wax at the bottom of the tin is fully mixed in. Pour out into the
mixing buckets enough topcoat to cover the perimeter of the roof (including the edge trims.) Use a 70mm application roller to coat the trims.
A roller will get a better and more even finish than a paintbrush. Roll the topcoat along the face of the trim. Hold the roller at an angle to the
bottom of the trim to cover half of the radius return on the front of the trim. To protect the fascia from topcoat, hold a piece of flashing trim
behind it as you topcoat the radius on the underside of the trim.
Calculate how much topcoat you will need to use to cover the main body of the roof. Add the required amount of hardener and stir well.
Using the 140mm application roller, cover the remaining laminate with just enough topcoat for the fibre pattern to be visible. Do not coat the
roof too thickly or the topcoat will crack. If a coloured topcoat is needed rather than the standard graphite grey, a colour pigment will need to
be added to a clear topcoat. A 20kg tin of topcoat requires 2kg of colour pigment. It is essential to mix the pigment thoroughly into the topcoat
to avoid patchiness and uneven colour.
Cleaning Tools and Equipment
Buckets can be re-used for many jobs. When hardener is added to each mix, coat the entire inside of the bucket. When the resin has cured
after approximately 30 minutes it can be peeled out, leaving the bucket like new and ready for the next job.
Paintbrushes can be dropped into a re-sealable container of acetone and left for the next job. Use only paintbrushes that have unpainted or
uncoated handles, as the coatings will come off and contaminate the resin. Application rollers have sleeves that are removable. It is too time
consuming to clean the roller sleeves. Unscrew the nut with pliers and drop the used sleeve into the bucket of used resin.
Either use disposable latex gloves when handling hardener or resins or clean hands with hand cleaner. Do not clean hands with acetone. Wipes are
also a useful addition to your toolkit. As well as cleaning hands they are good for removing uncured resin splashes from windows and fascias.
Slip Resistant Finishes:
Slate Granules can be used with Cure It Topcoat to achieve an Exposed Aggregate or Coated Aggregate finish (Coated with Topcoat).
For the best finished appearance avoid coating the perimeter of the roof and the trims with aggregate, and retain a smooth finish. To
achieve this, the trims should be topcoated before the granulated slate is applied, along with the first 100mm of the roof inbound of
the edge. When the topcoat has cured, use 50mm masking tape to neatly mask off the topcoated area of the roof, and then follow the
instructions below for the required finish:
Exposed Aggregate
Apply the topcoat to the roof in metre wide strips starting away from the access point at the usual rate of 0.4kg/m². After the first metre
run, sprinkle the granulated slate over the topcoat using 0.75kg/m² allowing a 200mm border adjacent to the un-topcoated area of the
roof. The border will prevent the next run of topcoat being applied onto the roof from becoming contaminated by the slate granules.
Continue to apply topcoat to the next metre strip and apply the granules to cover the previous border and leave another 200mm border
on the next strip. Repeat with subsequent runs working towards the access point.
Curing time will vary. This can take at least 20-30 minutes in warmer weather and may be an hour or longer in colder conditions. Ensure
that the topcoat has completely cured before sweeping the excess granules together and collecting the excess in a bag or bucket to use
on the next job. Remove the masking tape from the perimeter. (See pic on page 6).
Coated Aggregate
Apply the topcoat to the roof in metre wide strips starting away from the access point at the usual rate of 0.4kg/m². After the first run
sprinkle the granules over the area at a rate of 0.15kg/m². Roll the granules into the run of topcoat with the application roller.
Repeat this process for subsequent runs to complete the roof. The granules will cure into the topcoat. Remove the masking tape from the
perimeter of the roof once the roof has cured.
DO NOT LEAVE ACETONE IN OPEN CONTAINERS. IT IS HIGHLY FLAMMABLE